The disclosure relates generally to accelerometers, and more particularly, to an insulated accelerometer assembly for a vibrating component in a high voltage environment.
Large industrial machines such as dynamoelectric machines (e.g., generators and motors) vibrate during operation such that monitoring of the vibrations is desired. For example, it is advantageous to monitor vibrations in a generator stator end winding. Because of the high voltage environment, this vibration monitoring is traditionally accomplished using fiber-optic based devices. These fiber-optic devices may use a variety of fiber-optic technologies such fiber bragg grating, intensity based, Fabry-Perot interferometers, etc. and typically measures in 1 or 2 axes. A significant number of sensors, e.g., a minimum of 6, per generator end are needed to gather an accurate representation of the stator end winding vibration. The need for so many expensive fiber-optic sensors leads to costly systems.
Electrical accelerometers, such as Piezoelectric or Micro Electro-Mechanical system (MEMs), are well-known systems to detect motion, and are significantly less expensive than fiber-optic based accelerometers. Accelerometers output signals indicative of the force/motion and are operatively connected to vibrating components for receipt of the signals. Use of electrical accelerometers in high voltage areas such as a generator end winding, however, presents a number of challenges because the sensors can offer a path to ground for the high voltage that can result in harmful scenarios. For example, these accelerometers may present a path for voltage discharge, voltage tracking and/or coronas that may potentially damage end winding components. Devices have been created to provide protection for the accelerometer so they can be used in a high voltage environment, but they require highly complex structural configurations.